Sealing plug for an outlet opening of a container and container having a sealing plug

ABSTRACT

The invention relates to a sealing plug for an outlet opening of a container which accommodates a liquid melt. The sealing plug has a sealing region disposed on the outer surface thereof that is configured to come into contact with a section of the delimiting wall delimiting the outlet opening in order to close the outlet opening. The sealing plug narrows from the sealing region towards a front end along the longitudinal axis of the sealing plug. The front end is configured for insertion into the outlet opening, wherein a section between the sealing region and the front end is designed to have a concave shape.

The invention relates to a sealing plug for an outlet opening of a container adapted to receive a liquid melt or other fluids (gases and liquids) loaded with solids, which has a sealing region on its outside surface which is configured to come into contact with a section of the boundary wall delimiting the outlet opening to close the outlet opening and which tapers along its longitudinal axis from the sealing region to a front end which is configured to be inserted into the outlet opening. The invention also relates to a container for receiving a melt or other fluids (gases and liquids) loaded with solids, in which an outlet opening is formed which is delimited by a boundary wall, and which has a sealing plug for closing the outlet opening, wherein the sealing plug has a sealing region on its outside surface configured to come into contact with a section of the boundary wall delimiting the outlet opening to close the outlet opening, and which is tapered along its longitudinal axis from the sealing region to a front end which is configured to be inserted into the outlet opening. The invention also relates to the use of such sealing plugs and/or the use of such containers.

It is known in the technical field of handling metal melts that solid particles may be dispersed in metal melts which can deposit on the walls of systems through which the metal melts flow, for example on the walls of the outlet opening, for example, when flowing out of a container through its outlet opening.

WO 2005/042189 A2 discloses a sealing plug for an outlet opening of a container receiving a liquid melt, which has a sealing region and wherein its outside surface configured to come into contact with a section of the boundary wall delimiting the outlet opening to close the outlet opening, and which is tapered along its longitudinal axis from the sealing region to a front end configured to be inserted into the outlet opening. WO 2005/042189 A2 also discloses a container for receiving a melt in which an outlet opening delimited by a boundary wall is formed, and wherein the container has a sealing plug for closing the outlet opening, wherein the sealing plug has on its outside surface a sealing region which is configured to come into contact with a section of the boundary wall delimiting the outlet opening to close the outlet opening, and wherein the sealing plug is tapered along its longitudinal axis from the sealing region to a front end that is configured to be inserted into the outlet opening.

According to WO 2005/042189 A2, the aforedescribed problem associated with deposits of solid particles of metal melts is presumably solved by providing corrugations on the surface of the sealing plug or on the surface of the boundary wall delimiting the outlet opening which are arranged such that, when the sealing plug is lifted, the size of the passage channel formed between the outside surface of the sealing plug and the boundary wall of the outlet opening becomes discontinuously larger the farther the respective part of the passage channel is removed from the contact point between the sealing plug and the boundary wall when the sealing plug is closed. With the wavy stepped structure of the surface of the sealing plug, the design according to WO 2005/042189 A2 is intended to cause the flow flowing past the surface of the sealing plug to detach at certain locations along the surface, because the surface suddenly springs back at these points and causes formation of turbulent vortices at the surface of the sealing plug. WO 2005/042189 A2 teaches that the controlled turbulences at the surface of the sealing plug reduce the blockage rate at the surface of the sealing plug by continuously carrying away nonmetallic particles. WO 2005/042189 A2 moreover states that when gases are—potentially—present, the controlled turbulences in the region of the sealing plug surface distribute the gas bubbles uniformly about this part of the sealing plug and thereby aid in the prevention of blocking deposits.

Plug geometries, wherein the sealing plug has a spherical or conical tip, are also known from practical applications.

In view of this background, it was the object of the invention to propose a sealing plug for an outlet opening of a container receiving a liquid melt, as well as a container for receiving a melt, which reduces deposition of particles when a fluid loaded with particles flows through such system. The use of such sealing plug and/or such container is also discussed.

This object is solved by the independent claims 1, 9 and 12. Advantageous embodiments are recited in the dependent claims and the following description.

The invention is based on the concept that blockage of flow-through discharge systems has, among others, a flow-related cause, namely recirculation regions on the boundary wall of the outlet opening below the plug which are produced by flow separation with resulting local maxima of the flow velocity at the center of the core flow below the plug. The invention is based on the premise that this causes increased deposition of particles on the interior wall of the flow-through system.

The sealing plug according to the invention has an outside contour designed to efficiently guide the flow. In a preferred embodiment, the fluid flowing past the sealing plug is directed by the outside contour of the sealing plug so that the flow is parallel to the longitudinal axis of the sealing plug. In a preferred embodiment, the front end of the sealing plug is delimited from the additional surface shape of the sealing plug by a sharp edge. As a result, the flow separates at this location, but only at this location. This can prevent the formation of a velocity maximum below the plug.

The sealing plug according to the invention has a concave-shaped section located between the sealing region and the front end. Alternatively or in addition, the sealing plug is constructed so that the sealing region is located in a concave-shaped section of the sealing plug. The sealing plug then assumes a plug geometry which can be easily manufactured and which also makes it possible to guide the flow in the outlet opening parallel to the boundary wall of the outlet opening. This can prevent the creation of velocity maximum in the center of the core flow. A more stable flow guidance can also be attained with the invention. Moreover, the formation of sediments can also be prevented or minimized. The term concave-shaped section of the sealing plug refers in particular, and preferably, to a section which in an intersecting plane of the sealing plug has a contour containing the longitudinal axis of the sealing plug, wherein all surface points are located on the contour on one side of a straight line connecting the origin and the end point of the contour.

The sealing region may be a surface region. The sealing region is frequently designed so as to create—in cross-section—a sealing point or—in relation to the surface of the sealing plug—a sealing line, through which the sealing plug can come into contact with a boundary wall of an outlet opening.

In a preferred embodiment, the surface of the sealing plug in the region between the end of the sealing region distal from the front end and immediately before the front end is designed so as to have only continuous shape changes. A continuous shape change refers in particular to such shape changes where a first smooth surface transitions into a second smooth surface without forming a transition surface. In particular, a continuous shape change refers to such shape changes where a first smooth surface transitions into a second smooth surface without forming a transition surface wherein the radius of the contour of the transition radius is smaller than the longitudinal extent of the first surface or smaller than the longitudinal extent of the second surface, wherein longitudinal extent refers to the extent of the surface away from the transition surface. A continuous shape changes also refers in particular to any type of shape change where a flow flowing along a surface region that includes a shape change does not detach. A continuous shape change can result in particularly good flow guidance.

In a preferred embodiment, the sealing plug according to the invention has only a single concave section in the region between the end of the sealing region distal from the front end and immediately before the front end. In this way, particularly good flow guidance can be achieved.

In a preferred embodiment, the concave-shaped section is formed substantially by an arc of a circle or a section of an ellipse or a section of a parabola in a cross-section through the sealing plug in a plane that includes the longitudinal axis of the sealing plug. This also aids in guiding the flow. In a preferred embodiment, the arc of a circle, the section of the ellipse, and/or the section of the parabola are formed by the arc of the section of the circle, the arc of the section of the ellipse, or the arc of the section of the parabola, wherein the section of the circle or the section of the ellipse or the section of the parabola has an angle of at least 10°, in particular preferred of at least 25°, and particularly preferred of at least 45°.

In a preferred embodiment, the sealing plug has a substantially cylindrical section located between the concave-shaped section and the front end. This can promote good flow guiding. In a preferred embodiment, the cylindrical part of the sealing plug is formed immediately adjacent to the front end. In a particularly preferred embodiment, the sealing plug according to the invention has a single concave-shaped section, which is joined directly to a cylindrical section of the sealing plug, and to which, in a particularly preferred embodiment, the front end is joined.

In a preferred embodiment, the front end has a flat surface located in a plane which is oriented perpendicular to the longitudinal axis of the sealing plug. In a particularly preferred embodiment, the front end is formed entirely by such flat surface. In an additional or alternative, also preferred embodiment, the front end may have an end face with a concave inward curvature. In a particularly preferred embodiment of this alternative embodiment, the entire front end is formed by an end face of the plug with a concave inward curvature.

In a particularly preferred embodiment, a convex section is arranged above the sealing region. With such convex section, in a preferred embodiment where the sealing region of the sealing plug is located in a concave section of the sealing plug, this sealing region of the sealing plug may transition via the joined convex section into the additional, primarily cylindrical upper part of the sealing plug. However, the invention is not limited to use with sealing plugs having a substantially cylindrical base body.

In a preferred embodiment, the radius of the concave-shaped section is greater than half the difference between the cross-section of the sealing plug at the end of the sealing region distal from the front end and the cross-section of the front end. This contributes to particularly good guidance of the flow.

In a preferred embodiment, a fluid outlet opening is disposed on the front end of the sealing plug through which a fluid that flows through a feed line in the sealing plug can exit. For example, argon may be discharged from such fluid outlet opening.

The container according to the invention for receiving a melt has a sealing plug, wherein the outside contour of the sealing plug and the shape of the outlet opening are matched such that the melt flowing into the outlet opening when the sealing plug is lifted far enough to form a gap between the outside surface of the sealing plug and the boundary wall, while the sealing plug is still inserted with its front end in the outlet opening, has in the region of a flow region adjacent to the boundary wall a flow direction which is oriented substantially parallel to the boundary wall. With this guidance of the flow, the deposition of particles on the boundary wall can be prevented.

In a preferred embodiment, the outer contour of the sealing plug and the shape of the outlet opening are matched to each other so that a gap is formed between the outside surface of the sealing plug and the boundary wall when the sealing plug is lifted to a point where, while the front end of the sealing plug is still inserted in the outlet opening, wherein the gap cross-section expands like a diffuser towards the front end. In this way, the flow is controllably delayed.

In an alternative or additional embodiment of the container according to the invention, the container has a sealing plug with at least one feature of the aforedescribed sealing plug according to the invention. By combining the measures realized on the sealing plug with the measures that can be implemented on the boundary wall of the container and by matching these measures to one another, a particularly good flow guidance can be attained.

In a particularly preferred embodiment, the sealing plug according to the invention is used with a container for receiving a liquid metal melt. In a particularly preferred embodiment, the container according to the invention is used for receiving a liquid metal melt. It has been observed that, particularly in applications with metal melts, the guidance of the flow achieved with the sealing plug according to the invention and/or the container according to the invention advantageously reduces the deposit on the walls of the system. The sealing plug according to the invention and the container according to the invention can advantageously also be used with other fluids (gases and liquids) that are loaded with solid matter.

The invention will now be described with reference to the drawings which show only exemplary embodiments. It is shown in:

FIG. 1 a, b a cross-sectional schematic diagram of a practical sealing plug in engagement with the outlet opening of a container for receiving a melt,

FIG. 2 a cross-sectional schematic diagram of a sealing plug constructed according to the invention in engagement in the outlet opening of a container for receiving a melt,

FIG. 3 a perspective view of a sealing plug according to the invention,

FIG. 4 a cross-sectional schematic diagram through a first embodiment of the a sealing plug according to the invention in engagement in the outlet opening of a container for receiving a melt, and

FIG. 5 a cross-sectional schematic diagram of a second embodiment of a sealing plug according to the invention in engagement in the outlet opening of a container for receiving a melt.

FIGS. 1 a, 1 b and 2 illustrate the flow conditions created by the geometry of the sealing plug and the shape of the outlet opening. The recirculation regions are shown by the dashed lines. As seen from FIGS. 1 a and 1 b, wall-proximate recirculation regions are formed in conventional sealing plugs. With the sealing plug according to the invention, an upward flow can be established in the embodiment illustrated in FIG. 2 below the flat front end (plug bottom), where particles or inclusions can increasingly collect. However, a deposition of these particles on the plug bottom itself can be prevented, for example, by discharging a fluid at a fluid outlet opening located at the front end of the plug. The shape of the conventional sealing plug illustrated in FIG. la has a spherical front end. The shape of a conventional sealing plug illustrated in FIG. 1 b has a conical front end.

The structures of the sealing plug according to the invention illustrated in FIGS. 2, 3, 4, 5 have a sealing region 3 on their outside surfaces which is designed to come into contact with the section of the boundary wall 1 delimiting the outlet opening in order to close the outlet opening. The illustrated sealing plug is tapered along its longitudinal axis from the sealing region to a front end which is designed to be inserted into the outlet opening. A concave section 4 is arranged between the end of the sealing region 3 distal from the front end and the front end. The sealing region 3 itself is arranged in this concave section 4 of the sealing plug. The sealing plug has a sealing point. The plug seals the outlet opening at the sealing point. When the sealing plug is lifted, the narrowest gap is located at this point, whereby the volume flow can be controlled by way of the provided gap area.

The concave section 4 in form of an arc of a circle deflects the melt and causes the melt to flow parallel to the boundary wall of the outlet opening at the transition into a cylindrical section 5 which is joined to the concave section 4. A sharp edge 6 where the cylindrical section 5 transitions into the front end of the sealing plug formed by a flat surface causes the flow to detach from the sealing plug contour. The point of detachment is defined by the sharp edge. From there, the melt flows parallel to the wall. A convex section 2 is arranged above the sealing region 3. An outlet opening 7, from which a fluid flowing through a feed line disposed in the sealing plug can exit, is arranged at the front end of the sealing plug formed by a flat surface. This fluid outlet opening 7 can be used to supply argon.

In the embodiment illustrated in FIG. 4, the sealing point is located at a 45° tangent of the boundary wall of the outlet opening. In the variant illustrated in FIG. 5, the sealing point is located at a 30° tangent of the boundary wall of the outlet opening. This sealing point of the second variant is frequently used in practical applications of sealing plugs. 

1.-12. (canceled)
 13. A sealing plug for an outlet opening of a container which receives a liquid melt, the sealing plug comprising: an outside surface defining a sealing region, said sealing region configured to contact a section of a boundary wall that delimits the outlet opening for closing the outlet opening, wherein the sealing region is tapered along a longitudinal axis of the sealing plug from the sealing region to a front end of the sealing plug constructed to be inserted in the outlet opening, wherein a first section of the sealing region extending between the sealing region and the front end has a concave shape or wherein the sealing region is located in a concave-shaped section of the sealing plug, wherein a radius of the concave-shape first section is greater than half a difference between a cross-section of the sealing plug at the sealing region distal from the front end and a cross-section of the front end.
 14. The sealing plug of claim 13, wherein a surface of the sealing plug has only continuous shape changes in a region between an end of the sealing region distal from the front end and immediately before the front end.
 15. The sealing plug of claim 13, wherein a second substantially cylindrical section is located between the concave-shaped first section and the front end.
 16. The sealing plug of claim 13, wherein the front end has a flat surface located in a plane which is oriented perpendicular to a longitudinal axis of the sealing plug.
 17. The sealing plug of claim 16, wherein the flat surface is an end face of the substantially cylindrical second section arranged between the concave-shaped first section and the front end.
 18. The sealing plug of claim 13, wherein a convex-shaped section is arranged above the sealing region.
 19. (canceled)
 20. The sealing plug of claim 13, further comprising a fluid outlet opening arranged at the front end and a feed line, with a fluid which flowing through the feed line exiting through the fluid outlet opening.
 21. A container for receiving a melt, comprising: a boundary wall delimiting an outlet opening, and a sealing plug having a longitudinal axis and a contoured outside surface defining a sealing region configured to come into contact with a section of the boundary wall for closing the outlet opening, wherein the sealing plug is tapered along the longitudinal axis from the sealing region to a front end of the sealing plug constructed to be inserted into the outlet opening, wherein the contoured outside surface of the sealing plug and a shape of the outlet opening are matched to one another and define a gap therebetween when the sealing plug is partially lifted out of the outlet opening while the front end of the sealing plug is still inserted in the outlet opening, such that the melt flowing into the outlet opening has a flow direction in a flow region adjacent to the boundary wall that is oriented substantially parallel to the boundary wall, wherein a first section of the sealing region extending between the sealing region and the front end has a concave shape or wherein the sealing region is located in a concave-shaped section of the sealing plug, wherein a radius of the concave-shape first section is greater than half a difference between a cross-section of the sealing plug at the sealing region distal from the front end and a cross-section of the front end.
 22. The container of claim 21, wherein the gap widens towards the front end.
 23. (canceled)
 24. A container for receiving a melt, comprising: a boundary wall delimiting an outlet opening, and a sealing plug having a longitudinal axis and a contoured outside surface defining a sealing region configured to come into contact with a section of the boundary wall for closing the outlet opening, wherein the sealing plug is tapered along the longitudinal axis from the sealing region to a front end of the sealing plug constructed to be inserted into the outlet opening, wherein a first section of the sealing region extending between the sealing region and the front end has a concave shape or wherein the sealing region is located in a concave-shaped section of the sealing plug, wherein a radius of the concave-shape first section is greater than half a difference between a cross-section of the sealing plug at the sealing region distal from the front end and a cross-section of the front end. 